My 900cc Cinquecento seems to have developed a tendency to overheat in traffic because the cooling fan doesn't cut in early enough. After coming home from a recent test run I let it sit on the drive for ten minutes or so, and the temperature was heading past 120C (by the internal gauge) with no sign of the fan; so I turned off the engine to stop it overheating and *then* the fan comes on... (Water was coming out past the expansion tank cap, so it's not just that the temp gauge is lying to me; the engine really is too hot.)
It's not the temperature sensor thingy, because I tried changing that with no effect (and testing the old and new ones with the aid of a pan of boiling water and a thermometer showed them both going to zero resistance at the 90-somethingC they're supposed to). And it's not that the fan doesn't work at all, because it does come on eventually. Another thing it definitely isn't is the thermostat, because I've just replaced that for being stuck open (with the old stat the car was running way under temp on motorways and then overheated when you stopped).
So I'm a bit stuck as to what else the problem could be -- can anybody suggest anything else?
Thanks in advance
-- Peter
It's not the temperature sensor thingy, because I tried changing that with no effect (and testing the old and new ones with the aid of a pan of boiling water and a thermometer showed them both going to zero resistance at the 90-somethingC they're supposed to). And it's not that the fan doesn't work at all, because it does come on eventually. Another thing it definitely isn't is the thermostat, because I've just replaced that for being stuck open (with the old stat the car was running way under temp on motorways and then overheated when you stopped).
So I'm a bit stuck as to what else the problem could be -- can anybody suggest anything else?
Thanks in advance
-- Peter